1. Field of Invention
The present invention relates to the field of computer multi-OS (Multiple Operating System) technology, in particular to a computer multi-OS switching method.
2. Description of Prior Art
Along with the advance of computer technology, it is now possible to achieve multi-function applications, such as application for simultaneously implementing an OS of household appliance mode and an OS of computer mode, in a computer by loading multi-OSs into the computer. With the computer multi-OS application popularized, the requirement on the time needed for switching between multi-OSs in the computer becomes more and more stricter. However, the switching of time of existing multi-OSs computer cannot meet such requirement.
The switching process between OSs in a computer actually comprises turning off one of the OSs, restarting the basic input/output system (BIOS) and then entering another OS. FIG. 1 shows the switching process between multi-OSs in a computer, which has the following specific steps assuming that two OSs are OS-1 and OS-2, respectively.
In step 100-101, the computer is powered on, BIOS initializes hardware devices in the computer and detects hard disk, and then BIOS judges the location of OS-1 (or OS-2) in the hard disk and acquires OS-1 (or OS-2);
In step 102, OS-1 (or OS-2) reads file data associated with itself from the hard disk to a random access memory (RAM), detects the hard disk and starts up;
In step 103, OS-1 (or OS-2) is turned off;
In step 104, the computer is reset, and BIOS once more initializes hardware devices in the computer, detects hard disk, and then judges the location of OS-2 (or OS-1) in the hard disk and acquires OS-2 (or OS-1);
In step 105, OS-2 (or OS-1) reads file data associated with itself from the hard disk to the RAM, detects the hard disk and starts up;
In step 106, the switching between the two Operating Systems is completed.
If there are three or more OSs to be switched, it is necessary to provide a user with a step for selecting which OS to be started or a step for alternately selecting an OS before the step 104 such that the computer is informed of the OS to be switched to and then executes the steps 104-106 to complete the OS switching process.
Since the switching process between multi-OSs in a computer is equivalent to the restart of the computer, the switching time for multi-OSs equals to the sum of time for restarting the computer twice. This leads to an excessive long switching period between multi-OSs in the computer, the period during switching the computer OSs equals to the sum of the two restarting period of the computer. Further, due to the same reason that the switching process between multi-OSs in a computer is equivalent to a restart of the computer, the user cannot save any running environment information (CONTEXT) in the OS before switching operation, and hence the user cannot continue his or her operation based on any saved CONTEXT when switching to the OS again.
At present, there is another method for computer multi-OS switching, in which the running environment of present computer OS is first suspended to a hard disk (STD) so as to put the OS into a sleeping state. At the time of switching back to the OS, the computer is reset. BIOS initializes hard devices in the computer, detects the hard disk, obtains the OS from the hard disk and copies its running environment into a RAM. The OS is restarted from the RAM based on the OS and its running environment. This method, however, also requires BIOS of the computer to initialize the hard devices and detect the hard disk, thus the time for switch OS is relatively long.